Rotary switch



' May 29, 1928. 1,671,389

R. K. WINNING ROTARY SWITCH Filed July 16, 1924 WNTOR.

g -M W 5)? A TTORNEYS Patented May entree mm OFFICE.

ROBERT K. WINNING, F MILWAUKEE, WISCONSIN, ASSIGNOR T0 CLUM MANUFAC- TURING COMPANY,0F MILWAUKEE, VIISCONSIN.

ROTARY swiron.

Application filed July 16,1924. Serial No. 726,269;

This invention relates to improvements in electric switches of the rotary type.

It is the primary object of this inventlon to provide a novel and simplified construc-.

preserving nevertheless a sturdiness of construction ensuring long life and satisfactory operation.

In the drawings:

Figure 1 is a fragmentary transverse section through a switch casing embodying an electrical switch mechanism incorporating this invention.

Figure 2 is a section taken on line 2-2 of V Figure l.

Figure 3 is a detail view taken on the section indicated at 33 in Figure 2.

Figure 4 is a detail view taken on tion indicated at it-d in Figure 3.

Figure 5 is a detail view in side elevation of the switch operating member.

Like parts are identified by the same reference characters throughout the several views.

The switch casing will be described but briefly since its. construction forms no part of the particular invention to be claimed in this ap 'ilication The paiticularv casing illustrated adapted to contain more than one switch and includes a body member comprising the side wall of the casing and stamped to provide a recess 11 in which the switch hereinafter to be described is dis posed. An integral flange 12 is connected the see by bolts or screws, such as that indicated at 13, with a fiber back 14 in which are embedded suitable metallic contact bushings 15 and 16 which comprise terminals for an electric circuit to be controlled by the switch. Equidistant between the terminals 15 and 16 a pin 17 knurled at 18 and projecting inwardly into the casing. Spot-Welded or otherwise fastened as at 19 to a flange 20 on the casing wall 10 is a disk 21 apertured at 22. A bezel 23 retains a glass finishing plate 24 in contact with a backing 25. The bezel is provided with a tongue 27 bent about the peripheral margin of the disk 22 to hold the parts in assembled relation. The same. function is performed also by means of a bush ing 29 made in the form of an eyelet andupset at 30 and 31to overlie respectively the glass plate 24 and the disk 22. 1

The switch actuating member comprises a short length of shaft 35 journaled in the bushing 29. The shaft is peripherally grooved at 37 to provide a portion of, reduced diameter, beyond'which .there is aknurled head 38 adapted to be grasped by the fingers of an operator. The knurled head is of the same or slightly less diameter than the shaft 35 and is integrally formed therewith.

Upon theshaft I provide an integral col-' lar 4d) beyond which projects a switch actuating head 41 and supporting shoulders 42. The head is rectangular in cross section, as isshown in Figure 2, and is thereby adapted for engagement in a correspondingly formed aperture in the floating contact hereinafter to be described. The rectangular form of the headis adapted to key the switch actuating member to the floating contact and thereby to transmitrotative movement from the member to the contact. Any other cross sectional form adaptedto perform this function may be substituted for the rectangular shape illustrated. i p

The shoulders 42'are shaped, as best indicated in Figure 3, to provide a fulcrum for the floating contact. To this end they. have high points at 43 in a common transverse axial plane and from these high points the shoulders slope to either side. viously immaterialwhether the slope takes the form of thecurve illustrated but the illustrated construction is preferred.

For reasons here' iafter to be specified, head 41 is preferably also curved at its extremity to provide a transversely extending cylindrical surface as at 4:4:- The head is.

It is obextend tothe bottom of recess 45 and therefore does not interfere. with the resilient Confined between said washer and the intespring 48; Upon one face of the disk is a thin metal plate 55 havingears 56 bent about the disk to retain the plate inposition there- The disk is preferably provided with notches 57 in its periphery to'receive theears 56wvl1ereby to secure the plate 55against ro- -tation relative to the fiber disk,

H for thehead 44, with whichit i'sundesirable to make electrical contact.

The-plate 55,1nay be generally of a circular form, as shown, and is provided with a large central aperture 59 a1ford1ng clearance Aperture 59 is, therefore, slightlylarger than the aperture 51 in fiber disk 50. Y

7' -The disk'55 is provided integrally with contact members in, the form of protuberances 60'Wl11ClL1I1t1-y conveniently be formed by a stamping operation. These contact members are" spaced apart thesame distance as the metallic sleeves 1'5 and 16 in the back plate ofthe switch sort-hat in one position of rotation of thel floating contact the convex surfaces of theprotuberances 60 will ride into and be'partiallyreceived Within the open ends ofthe terminal sleeves .15 and 16. Thereby an electrical circuit will be completed betweenterminals 15 and 16through the'protuberances 60 and the metallic plate 55. The plate, however, is wholly insulated by its mounting oniiher disk 50 from all me ta llicfsurfaces other than the terminal'memhers 15 and 16.

Obviously, if the knurled knob 38 is turnedto rotate shaft? 35 the rotative move ment thereof" will be transmitted through head-41 tothe floating contact just described;

and such contact will be caused to rotate.

Initiallyt-he contact and the entire switch actuatingshaft 35 will have an axial movement against spring i8 in ,orderto permit the convex protuberances to rise out of the terminal members 15 and 16 in which they rest when the switch I is closed. As soon, however, as the contacts 60 have left the terminals they will ride overthe surface ofthe fiber back plate 14 to any desired rotative position. This type of switch, however, is'welLknown and needs no further description.

Indriving the terminal members 15 and 16- into the fiber back plate 14 of the switch itis conceivable that such members may not be perfectly flush with the surface of plate 14 upon which the floating contact rides. Furthermore, it is conceivable thatthe entire back plate 14 may be out of parallelism with the front face of the switch, or that some other conditions may obtain such as to prevent the shaft 35 from, being in itsusual position normal to; the; back plate 14. To make the switch perfectly operative in any sucin contingency so that the pressure of spring 48 may be transmitted alike to both ofthecontacts 60o1 the rotary switch member, the said member is fulcrumed as above described for oscillationon an axis transverse with respectto a'line drawn between the two pro'tuberances. or contactsGO. Thus,

regardless of any possible slightirregularities in the construction of the switch the pressure of spring 48' will always be transmitted to the moving contact in such a manner as to force such contact to adapt itself to the surfaces over which it operates. 1t

Wllhb; noted that to accomplish this result I- have provided-a fioatingcontact which is movable axially and rotatively and may be oscillated on a transverse axis, but which is secured against any tilting movement on an axis joining the: protuberances 60. If such tilting movement were possible, the SaldPOP- tions of plate 55 which connect contacts 60" to each other might touch the terminals 15 or 16 to the possible detriment of theswitch.

The floating'con'tact is therefore supported, I

against such tlltlllgfl'llOVGHlQIlll by means of the laterally spaced shoulders 42.-

The floating contact is likewise secured against radial movement in any direction. Thereby the contacts 60 are maintained invariably ina position for registry with the terminals 15 and16.

It will be notedthat the actuating shaft,35 requires nothing tomaintain it properly positio' ne'd within its bearing other than the re} action ofspring' 48, which furnishes the neoessary pressure for the switch contacts. The pin or stud 17; supports and positions shaft 35and is'engaged in theaperture 45 thereof when the backplate 14 is set in place. In the normal operation of the device, however, pin 17' does not limit the axial'movement of the shaft; If it did, it would prevent the contacts 60 from receiving the pressure of spring 48. Y

It will be noted that the entire device is very simply constructed and is easily assembled. The spring 48 and washer 47 are assembled on shaft 35 and the shaft is then thrust through the hushing29 in which it finds a bearing. As previously explained,

the knurled'head 38, by whichthe device is manually .grasped for operation, is no larger in diameter than the shaft so that this meth; 0d of assembly is facilitated, The floating contact is now positionedjionthe head'41and the back plate 14 is attached; to the casing member 10in such fashion that the pin 17 is received within aperture45 of the shaft. This completes the assembly of the switch and leaves it operative.

In the event that thefioating contact is caused to oscillate about its fulcrum on shoulders 42 during the operation of the switch, the head 41 which transmits rotative movement to the floating contact-might bind in the aperture 51 of fiber disk 50 if it were not for the fact that the said head 41 is provided with a cylindrically rounded surface 44 which affords clearance for any conceivable oscillation of the floating contact on its fulcrum mounting.

I claim:

1. In a device of the'character described, the combination with a rotor providing a fulcrum relatively fixed with reference to the rotor, of a dielectric member bearing on said fulcrum, and an electrical contact carried by said member.

2. In a device of the character described, the combination with a rotor provided with means defining a transverse fulcrum, of a di-electric member bearing against the fulcrum of the rotor, and an electrical contact carried by said member at one side of the axis upon which said member is fulcrumed.

3. In a device of the character described, the combination with a rotor and a spring arranged to urge said rotor axially, of a floating contact member fulcrumed to said rotor on an axis transverse with respect thereto and held to its fulcrum by the pressure of said spring transmitted through said rotor.

4. In a device of the character described, the combination with a rotor and a spring urging said rotor axially, a contact-carrying member provided with a fulcrum bearing on said rotor and splined thereto for rotation therewith, contacts on said members spaced upon either side of the fulcrum thereof, and means providing relatively stationary contacts adapted for interaction with the contacts carried by said member, said member being forced to a position for interaction with said stationary contacts through the pressure of said spring transmitted through said rotor and the fulcrum bearing of said member on said rotor.

5. In a device of the character described, the combination with a switch casing having a back plate provided with relatively fixed contacts and having a front plate provided with an aperture, of a switch actuating rotor extending through said aperture and provided with aligned fulcrum members upon either side of its axis, a spring urging said rotor toward said back plate, and a contact element confined between said fulcrum member and said back plate and operatively connected with said rotor for rotation there with, said contact element being provided with contacts adapted in one position of rotation thereto to register with the contacts of said back plate. 1

6. In adevice of the character described,

the combination with a switch casing having a back plate provided with relatively fixed electrical terminals and having an apertured front plate, of a rotor extending through said front plate, a spring urging said rotor axially in the direction of said back plate, said rotor being formed to provide a fulcrum transverse with respect to its axis, and a contact carrying member confined between said fulcrum and said back plate and including contacts adapted in one position of rotation for registry with the terminals of said back plate.

7. In a device of the character described, the combination with a contact member including a di-electric support and electrical contacts carried thereby, of a rotor including a centrally disposed head in splined relation to said support, and a-shoulder on either side of said head providing a fulcrum for said support, the splined connection between said head and the support being such as to permit said support to oscillate on said fulcrum. i

8. In a device of the character described, the combination with an apertured switch casing, of a switch actuating member comprising a shaft adapted to fit within the aperture of said casing and provided with an exposed manually engageable portion receivable through said aperture, and means formed'integrally with said shaft adapted for the support of a floating switch contact and the operative rotation thereof.

9. In a device of the character described,

the combination with anapertured switch casing, of a switch actuating member comprising'a shaft adapted to fit within the aperture of said casing, and having an manually engageable portion receivable through said aperture; a contact member within said casing in splined relation to said shaft; and means rigidly connected with said shaft providing a fulcrum bearing for said member upon which said member is adapted to oscillate while maintaining its splined connection with the shaft. i

10. In a device of the character described, the combination with an apertured switch casing, of a switch actuating member comprising a shaft adapted to fit within the aperture of said casing and having a manually engageable portion receivable through said aperture, a contact member within said casing in splined relation to said shaft, means rigidly connected with said shaft providing a fulcrum bearing for said member upon which said member is adapted to oscillate while maintaining its splined connection with the shaft, a pair of contacts supported from said member in operative electrical connection with each other and insulated from said shaft," anda: setv of electrical. terminals mounted in said switch casing and arranged: operatively for reg stry with. said contacts in one positionof I'OtflllLOILOf saidcshaftand a said member.

ll. In a device of the-character, described, the COHlblllfitlOIlJVlth a swltch casing. having an apertured face and. a] set; of electrical: terminals at, its back. at substantiallyequal radial distances from the projectedaxis of said apenturmof arotor comprlsing' ashaft;

projecting through said aperture and provided within said casingwith acentrally.

dis-posed head-and shoulders upon either side of. sad head providing an open fulcrum bearing a spring confined, between a portion of said shaft and, the front, of said casing, whereby to urge said shaft1 axially toward the rear of; said casing and a floatmg. electrical contact member provided with contacts adapted for'registry; with the ter-- Ininals of said casing, said. n'lembeu being confined between saidshoulders and back of said casing. i.

12. In a device of-the character described, the combination with-a. switch casing having an apertured face and a set of electrical ter 'minals at its back (at-substantially equal radial distances; from the projected-axis of 7 said aperture,,of arotor comprising a shaft projectingthrough said. aperture and provided, within said casing with a centrally disposed head and shoulders upon, either side of said head providing an openfulcrum bearing, a spring confined ,between a portion of said shaft and the front of; seal casing,

whereby to urges-aid shaft axially toward the rear of said casing a floating electrical contact; member provlded with. contacts adapted for registry withtheterminals of said casing,,said memberbeing; confined betweenv said shoulders and the hack of said casing and connorising a; di-electric support resting onsaid shoulders and. splinedto said head, and a metallic face plate-attached to said support and 1 tacts.

13., In a device of the character des,cr;ibed,. a switch actuatlng member compr s ng a shaft, a head of generally rectangular cross section and terminating in a surfacerounded about a transver-"e axis, said head being;

disposed. centrally of said shaft, and shoulder members formed integrally with said; head. upon either side thereof and having terminal portions rounded upon comnjlon vided with integral; protuberances constituting electrical contransverse; axis substantially. in, the plane, of said, first mentioned y axis.

14. In a device of the character described,

the combination with a; contact. member providing a. central opening, of; an. actuating rotor includinga: head conforming to said; opening; and adapted, to be fitted. therein,

and; a: pair of shouldersonopposite sides. of

said; head providedwith, terminal surfaces rounded upon a common transverse axis.

15v. InaQdeviceofthe character described, thecombinationwith a floating, switch cone tact comprising}awdirelectric support pro 7" vided with a central aperture,and a-metallic face plate connected with said support and carrying interconnectedI electrical; contacts, of an actuating-.member including a shaft having aiterminali portion splined within the aperture of saidlidi olectric support and a posed manually engageable portion receiv 5 able tl'1erethr0ugh,.a, spring acting upon said rotor in a direction to, press it "centrally of" said casing from said aperture a contact member: connected-withsaid rotor torreceive.

rotation. therefrom, v and: a terminal supported. by said casing in a position. to be con? tacted bysaldv member; said casing, being so; formed wlth reference to the length of said 1 rotor and of said spring; as) to. maintain: said spring;underrcompression.when said member I isin contact with saiditcrminali, 7

17. In, a device; offlthe, charactcn described,

the con'ibination with; a casing havingsepa rable front; and rear faces and; a' bearing,

aperture in its, front, face, of arotor jour nalled in,said1aperture and: having a, manu: ally engageable portion. ]Q1'Oj60ti1lg;fl16lfronn a spring confined between a 1 portion ,Ofl said rotor andithe front face'of thecasing'y whereby to press saidqrotor; rearwardly, and

acontact-member operatively adjustable with reference to the rear face ofthe casing; and interposed between the- 1'6211'3 face and. the rotor under the compression of said spring, the sepaaat-ion; of said front andrearp facesbeing adaptedi to permit: the removal of the rotor through'said aperture.

ROBERT K1. .WI-NN-ING; 

